27,114 research outputs found
Programmatic and Direct Manipulation, Together at Last
Direct manipulation interfaces and programmatic systems have distinct and
complementary strengths. The former provide intuitive, immediate visual
feedback and enable rapid prototyping, whereas the latter enable complex,
reusable abstractions. Unfortunately, existing systems typically force users
into just one of these two interaction modes.
We present a system called Sketch-n-Sketch that integrates programmatic and
direct manipulation for the particular domain of Scalable Vector Graphics
(SVG). In Sketch-n-Sketch, the user writes a program to generate an output SVG
canvas. Then the user may directly manipulate the canvas while the system
immediately infers a program update in order to match the changes to the
output, a workflow we call live synchronization. To achieve this, we propose
(i) a technique called trace-based program synthesis that takes program
execution history into account in order to constrain the search space and (ii)
heuristics for dealing with ambiguities. Based on our experience with examples
spanning 2,000 lines of code and from the results of a preliminary user study,
we believe that Sketch-n-Sketch provides a novel workflow that can augment
traditional programming systems. Our approach may serve as the basis for live
synchronization in other application domains, as well as a starting point for
yet more ambitious ways of combining programmatic and direct manipulation.Comment: PLDI 2016 Paper + Supplementary Appendice
Guidance on the principles of language accessibility in National Curriculum Assessments : research background
This review accompanies the document, which describes the principles which should guide the development of clear assessment questions. The purpose of the review is to present and discuss in detail the research underpinning these principles. It begins from the standpoint that National Curriculum assessments, indeed any assessments, should be:
- appropriate to the age of the pupils
- an effective measure of their abilities, skills and concept development
- fair to all irrespective of gender, language, religion, ethnic or social origin or disability. (Ofqual, 2011)
The Regulatory Framework for National Assessments: National Curriculum and Early Years Foundation Stage (Ofqual, 2011) sets out a number of common criteria which apply to all aspects of the development and implementation of National Assessments. One of these criteria refers to the need for assessment procedures to minimise bias: “The assessment should minimise bias, differentiating only on the basis of each learner’s ability to meet National Curriculum requirements” (Section 5.39, page 16). The Framework goes on to argue that: “Minimising bias is about ensuring that an assessment does not produce unreasonably adverse outcomes for particular groups of learners” (Annex 1, page 29). This criterion reinforces the guiding principle that any form of assessment should provide information about the knowledge and understanding of relevant content material. That is to say that the means through which this knowledge and understanding is examined, the design of the assessment and the language used should as far as possible be transparent, and should not influence adversely the performance of those being assessed.
There is clearly a large number of ways in which any given assessment task can be presented and in which questions can be asked. Some of these ways will make the task more accessible – that is, easier to complete successfully – and some will get in the way of successful completion. Section 26 of the Fair Access by Design (Ofqual, 2010) document lists a number of guiding principles for improving the accessibility of assessment questions, although the research basis for these principles is not made completely clear in that document. The aim of the current review is to examine the research background more closely in order to provide a more substantial basis for a renewed set of principles to underpin the concept of language accessibility.
In the review, each section will be prefaced by a statement of the principles outlined in Guidance on the Principles of Language Accessibility in National Curriculum Assessments and then the research evidence underpinning these principles will be reviewed
Fixed-Parameter Algorithms for Computing Kemeny Scores - Theory and Practice
The central problem in this work is to compute a ranking of a set of elements
which is "closest to" a given set of input rankings of the elements. We define
"closest to" in an established way as having the minimum sum of Kendall-Tau
distances to each input ranking. Unfortunately, the resulting problem Kemeny
consensus is NP-hard for instances with n input rankings, n being an even
integer greater than three. Nevertheless this problem plays a central role in
many rank aggregation problems. It was shown that one can compute the
corresponding Kemeny consensus list in f(k) + poly(n) time, being f(k) a
computable function in one of the parameters "score of the consensus", "maximum
distance between two input rankings", "number of candidates" and "average
pairwise Kendall-Tau distance" and poly(n) a polynomial in the input size. This
work will demonstrate the practical usefulness of the corresponding algorithms
by applying them to randomly generated and several real-world data. Thus, we
show that these fixed-parameter algorithms are not only of theoretical
interest. In a more theoretical part of this work we will develop an improved
fixed-parameter algorithm for the parameter "score of the consensus" having a
better upper bound for the running time than previous algorithms.Comment: Studienarbei
Generating Surface Geometry in Higher Dimensions using Local Cell Tilers
In two dimensions contour elements surround two dimensional objects, in three dimensions surfaces surround three dimensional objects and in four dimensions hypersurfaces surround hyperobjects. These surfaces can be represented by a collection of connected simplices, hence, continuous n dimensional surfaces can be represented by a lattice of connected n-1 dimensional simplices. The lattice of connected simplices can be calculated over a set of adjacent n-dimensional cubes, via for example the Marching Cubes Algorithm. These algorithms are often named local cell tilers. We propose that the local-cell tiling method can be usefully-applied to four dimensions and potentially to N-dimensions. We present an algorithm for the generation of major cases (cases that are topologically invariant under standard geometrical transformations) and introduce the notion of a sub-case which simplifies their representations. Each sub-case can be easily subdivided into simplices for rendering and we describe a backtracking tetrahedronization algorithm for the four dimensional case. An implementation for surfaces from the fourth dimension is presented and we describe and discuss ambiguities inherent within this and related algorithms
A Novel Distributed Representation of News (DRNews) for Stock Market Predictions
In this study, a novel Distributed Representation of News (DRNews) model is
developed and applied in deep learning-based stock market predictions. With the
merit of integrating contextual information and cross-documental knowledge, the
DRNews model creates news vectors that describe both the semantic information
and potential linkages among news events through an attributed news network.
Two stock market prediction tasks, namely the short-term stock movement
prediction and stock crises early warning, are implemented in the framework of
the attention-based Long Short Term-Memory (LSTM) network. It is suggested that
DRNews substantially enhances the results of both tasks comparing with five
baselines of news embedding models. Further, the attention mechanism suggests
that short-term stock trend and stock market crises both receive influences
from daily news with the former demonstrates more critical responses on the
information related to the stock market {\em per se}, whilst the latter draws
more concerns on the banking sector and economic policies.Comment: 25 page
Globular clusters in the outer halo of M31: the survey
We report the discovery of 40 new globular clusters (GCs) that have been
found in surveys of the halo of M31 based on INT/WFC and CHFT/Megacam imagery.
A subset of these these new GCs are of an extended, diffuse nature, and include
those already found in Huxor et al. (2005). The search strategy is described
and basic positional and V and I photometric data are presented for each
cluster. For a subset of these clusters, K-band photometry is also given. The
new clusters continue to be found to the limit of the survey area (~100 kpc),
revealing that the GC system of M31 is much more extended than previously
realised. The new clusters increase the total number of confirmed GCs in M31 by
approximately 10% and the number of confirmed GCs beyond 1 degree (~14 kpc) by
more than 75%. We have also used the survey imagery as well recent HST archival
data to update the Revised Bologna Catalogue (RBC) of M31 globular clusters.Comment: Accepted to MNRA
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